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Ricin

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RICIN
RICIN
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INTRODUCTION
INTRODUCTION
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Ricin is a potent cytotoxin that is synthesized in the edosperm cells
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Ricin is a potent cytotoxi that is synthesized in the endosperm cells of maturing Riccinus seeds(1). Ricin belongs to a small multi gene family(2) that is composed of eight members. It is also important to mention that Ricin is classified as a type II heterodimeric Ribosome Inactivatiing protein(1).
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of maturing Riccinus seeds(1). Ricin belongs to a small multi-gene family
+
-
(2) that is composed of eight members. It is also important to mention
+
-
that Ricin is classified as a Type II heterodimeric Ribosome Inactivating
+
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protein(1).
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STRUCTURE
STRUCTURE
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Ricin is a heterodimer that consists of a 32,000 dalton A chain
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Ricin is a heterodimer that consists of a 32,000 Dalton A chain glycoprotein linked by a disulfide bond to a 32,000 Dalton B chain glycoprotein(2). The A chain enzyme is a globular protein with extensive secondary structure and a predominate active site(2); where the B chain is a lectin(2) that binds to galactose-containing surface receptors(3).
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glycoprotein linked by a disulfide bond to a 32,000 dalton B chain
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glycoprotein(2). The A chain enzyme is a globular protein with extensive
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secondary structure and a predominate active site(2), where the B chain
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is a lectin(2) that binds to galactose-containing surface receptors(3).
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FUNCTION
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PHYSIOLOGY
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The mechanism employed by Ricin to gain entry to a host cell involves
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The mechanism deployed by Ricin to gain entry to a host cell uses the heterogenic properties given to the toxin. Firstly the toxin arranges itself in such a way where its B chain can easily interact with the host cells receptors, and once acknowledgement happens, the B chain can fascilitate transport of the A chain into the cytoplasm(2). This association between the A and B chain is essential for toxicity(2) without it the Ricin would not be able to gain access to the cells organelles rendering it useless. Once the A chain gains entry into the cytosol its mechanism for attack of the ribosome is depurination of a single endenosine residue in 28S Ribosomal RNA(3) and this inhibits protein synthesis
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the heterodimeric properties of the toxin. Firstly the toxin arranges
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itself in such a way where its B chain can easily interact with the host
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cells receptors and once this happens the B chain can fascilitate the
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transfer of the A chain into the Cytoplasm(2). This association between
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A and B chain is essential for toxicity(2) without it the Ricin would not be
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able to gain access to the cells organelles. Once the A chain gains entry into
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the cytosol its target of attack is the ribosome, and its mechanism involves
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depurination of a single endenosine residue in 28S ribosome RNA(3); which
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inhibits ribosome function, thus stopping protein synthesis.
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Revision as of 21:27, 31 March 2010

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                                                RICIN















INTRODUCTION

Ricin is a potent cytotoxi that is synthesized in the endosperm cells of maturing Riccinus seeds(1). Ricin belongs to a small multi gene family(2) that is composed of eight members. It is also important to mention that Ricin is classified as a type II heterodimeric Ribosome Inactivatiing protein(1).


STRUCTURE

Ricin is a heterodimer that consists of a 32,000 Dalton A chain glycoprotein linked by a disulfide bond to a 32,000 Dalton B chain glycoprotein(2). The A chain enzyme is a globular protein with extensive secondary structure and a predominate active site(2); where the B chain is a lectin(2) that binds to galactose-containing surface receptors(3).


PHYSIOLOGY

The mechanism deployed by Ricin to gain entry to a host cell uses the heterogenic properties given to the toxin. Firstly the toxin arranges itself in such a way where its B chain can easily interact with the host cells receptors, and once acknowledgement happens, the B chain can fascilitate transport of the A chain into the cytoplasm(2). This association between the A and B chain is essential for toxicity(2) without it the Ricin would not be able to gain access to the cells organelles rendering it useless. Once the A chain gains entry into the cytosol its mechanism for attack of the ribosome is depurination of a single endenosine residue in 28S Ribosomal RNA(3) and this inhibits protein synthesis
Please do NOT make changes to this Sandbox until after April 23, 2010. Sandboxes 151-200 are reserved until then for use by the Chemistry 307 class at UNBC taught by Prof. Andrea Gorrell.
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